diff --git a/Settings.php b/Settings.php
index 95e5edb..818891d 100644
--- a/Settings.php
+++ b/Settings.php
@@ -1,9 +1,9 @@
 <?php
 // 2016-06-29
 namespace Dfe\AllPay;
+use Df\Config\Source\WaitPeriodType;
 use Df\Payment\Settings\Options as O;
 use Dfe\AllPay\Source\Option as OptionSource;
-use Dfe\AllPay\Source\WaitPeriodType;
 use Zend_Date as ZD;
 /** @method static Settings s() */
 final class Settings extends \Df\Payment\Settings {
diff --git a/Source/WaitPeriodType.php b/Source/WaitPeriodType.php
deleted file mode 100644
index aefd428..0000000
--- a/Source/WaitPeriodType.php
+++ /dev/null
@@ -1,24 +0,0 @@
-<?php
-namespace Dfe\AllPay\Source;
-use Magento\Sales\Model\Order as O;
-// 2016-07-19
-/** @method static WaitPeriodType s() */
-final class WaitPeriodType extends \Df\Config\Source {
-	/**
-	 * 2016-07-19
-	 * @override
-	 * @see \Df\Config\Source::map()
-	 * @used-by \Df\Config\Source::toOptionArray()
-	 * @return array(string => string)
-	 */
-	protected function map() {return [
-		'calendar_days'=> 'Calendar Days', self::WORKING_DAYS => 'Working Days'
-	];}
-	
-	/**
-	 * 2017-03-19
-	 * @used-by \Dfe\AllPay\Settings::waitPeriodATM()
-	 * @used-by \Dfe\AllPay\Source\WaitPeriodType::map()
-	 */
-	const WORKING_DAYS = 'working_days';
-}
\ No newline at end of file
diff --git a/composer.json b/composer.json
index b687dfa..8cfdff6 100644
--- a/composer.json
+++ b/composer.json
@@ -1,6 +1,6 @@
 {
 	"name": "mage2pro/allpay"
-	,"version": "1.6.7"
+	,"version": "1.6.8"
 	,"description": "The «歐付寶 allPay» payment extension for Magento 2."
 	,"type": "magento2-module"
 	,"homepage": "https://mage2.pro/c/extensions/allpay"
@@ -11,7 +11,7 @@
 		"homepage": "https://mage2.pro/users/dmitry_fedyuk",
 		"role": "Developer"
 	}]
-	,"require": {"mage2pro/core": ">=2.8.13"}
+	,"require": {"mage2pro/core": ">=2.9.18"}
 	,"autoload": {"files": ["registration.php"], "psr-4": {"Dfe\\AllPay\\": ""}}
 	,"keywords": [
 		"allPay"
diff --git a/etc/adminhtml/system.xml b/etc/adminhtml/system.xml
index 4c0a106..23974d3 100644
--- a/etc/adminhtml/system.xml
+++ b/etc/adminhtml/system.xml
@@ -249,7 +249,7 @@ contain some other symbols.</p>
 					type='select'
 				>
 					<label>Wait Period Type</label>
-					<source_model>Dfe\AllPay\Source\WaitPeriodType</source_model>
+					<source_model>Df\Config\Source\WaitPeriodType</source_model>
 					<comment><![CDATA[You can set the working days with the<br/>«<b>General</b>» → «<b>General</b>» → «<b>Locale Options</b>» → «<b>Weekend Days</b>» option.]]></comment>
 					<depends><field id='enable'>1</field></depends>
 				</field>